English verb conjugation
COULD PREASCERTAIN

Regular verb: preascertain - preascertained - preascertained

Affirmation

Simple form	V-ing form
I could preascertain you could preascertain he could preascertain we could preascertain you could preascertain they could preascertain	I could be preascertaining you could be preascertaining he could be preascertaining we could be preascertaining you could be preascertaining they could be preascertaining
Perfect	V-ing perfect
I could have preascertained you could have preascertained he could have preascertained we could have preascertained you could have preascertained they could have preascertained	I could have been preascertaining you could have been preascertaining he could have been preascertaining we could have been preascertaining you could have been preascertaining they could have been preascertaining

Negation

Simple form	V-ing form
I could not preascertain you could not preascertain he could not preascertain we could not preascertain you could not preascertain they could not preascertain	I could not be preascertaining you could not be preascertaining he could not be preascertaining we could not be preascertaining you could not be preascertaining they could not be preascertaining
Perfect	V-ing perfect
I could not have preascertained you could not have preascertained he could not have preascertained we could not have preascertained you could not have preascertained they could not have preascertained	I could not have been preascertaining you could not have been preascertaining he could not have been preascertaining we could not have been preascertaining you could not have been preascertaining they could not have been preascertaining

Interrogative form

Simple form	V-ing form
could I preascertain? could you preascertain? could he preascertain? could we preascertain? could you preascertain? could they preascertain?	could I be preascertaining? could you be preascertaining? could he be preascertaining? could we be preascertaining? could you be preascertaining? could they be preascertaining?
Perfect	V-ing perfect
could I have preascertained? could you have preascertained? could he have preascertained? could we have preascertained? could you have preascertained? could they have preascertained?	could I have been preascertaining? could you have been preascertaining? could he have been preascertaining? could we have been preascertaining? could you have been preascertaining? could they have been preascertaining?

Interro-negative form

Simple form	V-ing form
could I not preascertain? could you not preascertain? could he not preascertain? could we not preascertain? could you not preascertain? could they not preascertain?	could I not be preascertaining? could you not be preascertaining? could he not be preascertaining? could we not be preascertaining? could you not be preascertaining? could they not be preascertaining?
Perfect	V-ing perfect
could I not have preascertained? could you not have preascertained? could he not have preascertained? could we not have preascertained? could you not have preascertained? could they not have preascertained?	could I not have been preascertaining? could you not have been preascertaining? could he not have been preascertaining? could we not have been preascertaining? could you not have been preascertaining? could they not have been preascertaining?